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Hurricane Season 2010: Tropical Storm Anggrek (Southern Indian Ocean)
11.04.10
 
November 4, 2010

Anggrek Tropically Depressed in the Southern Indian Ocean

This infrared image of Tropical Storm Anggrek was captured by the AIRS instrument aboard NASA's Aqua satellite on Nov. 3 › View larger image
This infrared image of Tropical Storm Anggrek was captured by the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA's Aqua satellite on Nov. 3 at 07:05 UTC (3:05 a.m. EDT). Strong, cold, high thunderstorm cloud tops (purple) circled the storm's center of circulation.
Credit: NASA/JPL, Ed Olsen
At 5 a.m. EDT on Nov. 4, the Joint Typhoon Warning Center noted it last location about 235 nautical miles south of the Cocos Islands near 15.4 South and 94.0 East. It was still moving at about 10 mph to the west-northwest and had maximum sustained winds near 34 mph. Satellite imagery shows that Anggrek's center is exposed to the outside winds that helped cause its breakdown. An exposed center of circulation is allows for weakening.

It is expected to dissipate in the next couple of days as it enters cooler waters and an area of stronger wind shear.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD











November 3, 2010

Tropical Storm Anggrek is Tightly Wrapped In NASA Satellite Imagery

This infrared image of Tropical Storm Anggrek was captured by the AIRS instrument aboard NASA's Aqua satellite on Nov. 3 › View larger image
This infrared image of Tropical Storm Anggrek was captured by the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA's Aqua satellite on Nov. 3 at 07:05 UTC (3:05 a.m. EDT). Strong, cold, high thunderstorm cloud tops (purple) circled the storm's center of circulation.
Credit: NASA/JPL, Ed Olsen
Bands of strong thunderstorms are wrapping around the center of Tropical Storm Anggrek in the Southern Indian Ocean, according to satellite imagery. NASA's Aqua satellite captured an infrared look at those strong thunderstorms today.

NASA's Aqua satellite passed over Anggrek on Nov. 3 at 07:05 UTC (3:05 a.m. EDT) and the Atmospheric Infrared Sounder (AIRS) instrument onboard captured an infrared image of the cold thunderstorms within the system. The image showed that strong, high thunderstorm cloud tops tightly circled the storm's center. There was also strong convection (rapidly rising air that forms the thunderstorms the power a tropical cyclone) along the southern edge of the low-level center of circulation.

At 0900 UTC (5 a.m. EDT), Tropical Storm Anggrek's maximum sustained winds were near 50 knots (57 mph) with higher gusts. It was about 140 nautical miles south of the Cocos Islands near 14.6 South and 96.9 East. It was moving southwest near 7 mph and is expected to continue moving in that direction.

Anggrek is in an area of moderate vertical wind shear (winds that can weaken and tear apart a tropical cyclone). By the weekend, Anggrek is forecast to steadily weaken and dissipate as it encounters cooler waters and stronger wind shear.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD



November 2, 2010

Tropical Storm Anggrek Out in Open Waters

AIRS showed Anggrek's warm waters, as warm as 80 degrees F (the threshold for maintaining tropical cyclones). › View larger image
NASA's Aqua satellite flew over Tropical Storm Anggrek on Nov. 1 at 07:17 UTC (3:17 a.m. EDT) and the AIRS instrument captured this infrared image that showed warm waters (orange) around it, as warm as 80 degrees F (the threshold for maintaining tropical cyclones). The strongest thunderstorms circled the center and were as cold as or colder than 220 Kelvin or minus 63F.
Credit: NASA/JPL, Ed Olsen
Tropical Storm Anggrek has passed the Cocos Islands and is headed away from all land areas. At 0600 UTC (2 a.m. EDT) on Nov. 2, Anggrek had maximum sustained winds near 55 knots (63 mph) and was moving southward at 5 knots (6 mph). It was located about 70 nautical miles southeast of the Cocos Islands, near 13.1 South and 97.7 East.

Multispectral satellite imagery shows convective banding, or wrapping of thunderstorms around the low level center of the storm. That's a sign that the storm is intensifying and the Joint Typhoon Warning Center has called for it to strengthen in the next 48 hours. After that time, it is expected to weaken due to increased wind shear.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD









br /> November 1, 2010

Infrared View of Southern Indian Ocean's Second Tropical Storm Reveals Icy Cloud Tops

AIRS showed Anggrek's warm waters, as warm as 80 degrees F (the threshold for maintaining tropical cyclones). › View larger image
NASA's Aqua satellite flew over Tropical Storm Anggrek on Nov. 1 at 07:17 UTC (3:17 a.m. EDT) and the AIRS instrument captured this infrared image that showed warm waters (orange) around it, as warm as 80 degrees F (the threshold for maintaining tropical cyclones). The strongest thunderstorms circled the center and were as cold as or colder than 220 Kelvin or minus 63F.
Credit: NASA/JPL, Ed Olsen
Visible image of Tropical Storm Anggrek was captured by AIRS on Nov. 1 at 0717 UTC › View larger image
This visible image of Tropical Storm Anggrek was captured by the Atmospheric Infrared Sounder Instrument on NASA's Aqua satellite on Nov. 1 at 0717 UTC (3:17 a.m. EDT). The strongest concentration of thunderstorms circle Anggrek's center, while bands of thunderstorms are evident tailing to the southeast.
Credit: NASA/JPL, Ed Olsen
Tropical Storm Anggrek is moving through open waters of the Southern Indian Ocean, and NASA's Aqua satellite captured took the temperature of its cloud tops to get an indication of how strong the storm has become. Anggrek is the second tropical cyclone of the Southern Indian Ocean cyclone season, which officially doesn't start until Nov. 15.

Cold thunderstorm cloud tops with a tropical cyclone are an indication of whether a storm is strengthening or weakening. Since Anggrek formed over the weekend, infrared satellite imagery has confirmed that its cloud tops have grown colder. That's an indication that there is stronger uplift in the storm (rapidly rising air that forms the thunderstorms that power a tropical cyclone) than there was 24 hours before.

NASA's Aqua satellite flew over Tropical Storm Anggrek on Nov. 1 at 07:17 UTC (3:17 a.m. EDT) and it was the Atmospheric Infrared Sounder (AIRS) instrument that captured data on the storm. In addition to the very cold cloud tops as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F), the infrared image revealed warm waters of more than 80 degrees Fahrenheit (threshold for maintaining tropical cyclones).

On Nov. 1 at 0900 UTC (5 a.m. EDT), Tropical Storm Anggrek had maximum sustained winds near 50 knots (57 mph) with higher gusts. It was located about 100 nautical miles north-northeast of the Cocos Islands near 10.9 South and 97.5 East and has tracked southward at 7 knots (8 mph). The storm has been able to strengthen because vertical wind shear has eased.

The Joint Typhoon Warning Center forecasts the storm to intensify into a cyclone before moving over cooler waters when it approaches 15.0 South and wind shear will increase thereafter. By the end of the week, those forecasters believe that environmental conditions will dissipate the storm in open waters.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD